Adjustable induction heating head for a coaxial cable



Oct. 13, 1970 c, MlLLER 3,534,198

ADJUSTABLE INDUCTION HEATING HEAD FOR A COAXIAL CABLE,

Filed NOV. 29, 1967 3 SheQts-S'neet 1 'INVENTOR d60/V/Q45 c. M/4466 BY 5M @w A TTOZA/EVfi ADJUSTABLE INDUCTION HEATING HEAD FOR A COAXIAL CABLE Tiled Nov. 29, 1967 L. c. MILLER Oct. 13, 1970 3 Sheets-Sheet 2 i I INVENTOR. ZfO/V/DAS C. M/e

Oct. 13, 1970 L. c. MILLER ADJUSTABLE INDUCTION HEATING HEAD FOR A CQAXIAL CABLE 3 Sheets-Sheet. 3

Filed Nov. 29, 1967 mm Qmwm mm S g V R & /w N Z w m M 7 a MA A United States Patent 3,534,198 ADJUSTABLE INDUCTION HEATING HEAD FOR A COAXIAL CABLE Leonidas C. Miller, 1321 Sombrero Drive, Monterey Park, Calif. 91754 Filed Nov. 29, 1967, Ser. No. 686,408 Int. Cl. Hb 9/02 US. Cl. 21910.79 9 Claims ABSTRACT OF THE DISCLOSURE An angularly adjustable head carried on one end of a coaxial cable supports a work coil for induction heating, whereby the work coil may be turned relative to the cable. A modified form of the apparatus permits additional turning of the coil about another axis.

This invention relates to an induction heating apparatus and is particularly directed to improvements in the maneuverability of an induction heating tool remotely stationed at the end of a coaxial cable.

My previous Pat. No. 2,866,880 dealt with a clamp fixture supporting an induction heating coil to an induction heating machine. By using this clamp fixture and a coaxial cable constructed in the manner disclosed by my Pat. No. 3,022,368, it is now possible to do brazing by induction heating at a place distant from the induction heating machine. However, these coaxial cables are relatively stiff and do not have suflicient flexibility for some jobs. Also, repeated bending and twisting of such coaxial cables adversely affects their electrical characteristics.

This device combines the advantages of the devices of the previous patents discussed above and supplements them by permitting rotational movement of the remote work coil without the necessity of twisting the cable.

In the drawings:

FIG. 1 is a perspective view showing a preferred embodiment of this invention.

FIG. 2 is a perspective view showing a modification.

FIG. 3 is a side elevation of the device in FIG. 2, shown on a larger scale.

FIG. 4 is a sectional plan view of the device of FIG. 1.

FIGS. 5, 6, 7 and 8 are transverse sectional views taken substantially on the lines 55, 66, 77 and 8-8 as shown in FIG. 4.

FIG. 9 is a sectional plan view of the device shown in FIG. 2.

FIG. 10 is a transverse sectional view taken substantially on the lines 1010 as shown in FIG. 9.

FIG. 11 is a transverse sectional view taken substantially on the lines 1111 as shown in FIG. 3.

Referring to the drawings, the induction heating tool assembly generally designated 10, may have one or more turns of hollow copper tubing and may be formed in any convenient manner to suit a particular job requirement. The ends 11 and 12 of the hollow copper tubing are brazed within parallel extension tubes 13 and 14, respectively. These extension tubes are clamped in spaced relationship by the means of insulating clamp 15 and by means of threaded fastenings 16 and 17.

A shell assembly generally designated 18, includes a tubular receptacle 19 with external threads 19a. This receptacle 19 is fitted to a support ring 20 and is attached by means of brazing 21 (See FIG. 5). Threaded fasteners 22 connect this ring 20 to a filler cap 23 having a central opening 24. A pair of concentric metallic tubes 25 and 26 are attached to ring 20 and define a gap 27 between them. The outer tube 25 forms a convenient handle for the manipulation of the tool 10. The circumference of one portion of the inner tube 26 is perforated with the round openings 28, said openings provide a passageway for coolant between channel 29 and the gap 27. O-rings 30 and 31 prevent leakage. A metallic cylinder 32 is fitted coaxially within and connected by means of brazing to the inner tube 26. Spaced between said tubes 25 and 26 and connected thereto is a terminal ring 33 with internal threads 34.

The internal threads 34 receive a split metallic nut 35. A retainer ring 36 formed of plastic material fits within a circumferential slot 37 around nut 35 and holds it together. By rotating the split nut 35, the shell assembly 18 is advanced axially to relieve the friction contact at shoulder 38 and to permit said shell assembly 18 to be adjusted circumferentially to any position.

An inner conductor assembly, generally designated 39, is positioned coaxially within shell assembly 18. A tubular receptable 40 similar to receptacle 19 extends out through the central opening 24 in the filler cap 23. Internal threads 41 on receptacle 40 receive a metal tubular member 42. An insulating sleeve 43 and the output terminal body 44 surround the internal conductor assembly 39. The sleeve 43 and the terminal body 44 are connected by the threads 45. Positioned between the internal conductor assembly 39 and the connected terminal body 44 and sleeve 45 is an insulating collet 46 and flexible tube 47. The flexible tube 47 is secured to the internal conductor assembly 39 by a series of rectangular grooves 48 and clamped down by the collet 46 which is caused to be tightened around the outer surface of tube 47 by connecting terminal body 44 to sleeve 45.

Ports 49 in the circumference of the terminal body 44 provide for a communication of coolant between channel 29 and passage 50. External threads 51 on the output terminal body 44 receive the coaxial cable housing 52. This coaxial cable housing 52 serves to clamp the coaxial cable assembly, generally designated 53, into position relative to the terminal body 44. Thus, the terminal body 44 and the split nut 35 cooperate to provide a means for mounting the shell assembly 18 with respect to the coaxial cable assembly 53 for relative axial turning movement. The cable assembly 53 is clamped by tightening the housing 52 to the external threads 51 on the terminal body 44 which causes the insulating collet 54 to be tightened around the outer surface of the cable assembly. Connected to the cable housing 52 is a braided sheath 55 which encompasses the coaxial cable assembly 53 for a short distance in order to provide support at the junction.

The coaxial cable assembly 53 is preferably of the form disclosed by my prior Pat. No. 3,022,368. A pair of concentric imperforate and flexible tubes 47 and 56 formed of an electrically insulating material provide passages 57 and 58, respectively, for coolant. Positioned within the inner passage 57 is the woven electrical conductor or lead 59 which may be tubular in form and positioned coaxially of the tubes 47 and 56.

Tubular member 42 is fitted coaxially within the electrical conductor 59, terminating at 60a. An electrical connection is thus established between the metallic member 42 and the woven conductor 59. A second tubularly formed electrical conductor or lead 60 is positioned within the coolant passage 58 between the tubes 47 and 56, and terminated at 61. A metallic sleeve 62 is coaxially positioned between the conductor 60 and the tube 47 to establish an electrical connection between the woven conductor 60 and the sleeve 62. Thus, tubular member 42 and sleeve'62 provide the means for electrically connecting the leads 59 and 60, respectively, to the inner conductor assembly and the shell assembly. A third concentric imperforate and flexible tube 63 fits coaxially about the tube 56 and provides the outside surface of the coaxial cable assembly. Both tube 63 and tube 56 extend to the terminal body 44 and terminate at 64.

Coolant delivered to passage 58 passes through cir- 3 cular openings 65 in the sleeve 62, through a passage 66, defined by the inner surface of the sleeve 62 and the outer surface of the insulating tube 47, through the interior of the terminal body 44 and then on into the circular openings 49.

A support member 67 is positioned within the interio of the electrical conductor 59. This support member 67 is formed of electrically insulating material similar to that of the imperforate tubes and preferably comprises a member having multiple openings so that coolant may flow freely between the interior and the exterior thereof. The support member 67 prevents collapse of the electrical conductor 59 upon flexure of the coaxial cable assembl 53.

The parallel extension tubes 13 and 14 are slidably mounted within the receptacles 40 and 19, respectively. Electrical contact is achieved by tightening the nuts 68 and 69 around the external threads 19a and 71, respectively, and the collets 74 on the receptacles. O-rings 72 and 75 prevent leakage at the joints. Extension tube 14 is allowed to rotate freely within the receptacle 40 during adjustment of the shell assembly 18 by loosening nut 69. Wrench flats 76 on the outer surface of the receptacle 40 assist in the loosening of the nut 69.

In the modified form of my invention, shown in FIGS. 2, 3, 9, and 11, the major portion of the device is identical. The shell assembly and internal conductor assembly have been modified to receive an entirely different induction heating tool assembly, generally designated 77. Included in this tool assembly 77 are two body members 78 and 79. These body members 78 and 79 are formed of a metallic material of identical shape and define a gap 80 between them. Hollow pasageways 81 and 82 are provided in the body members 78 and 79, respectively, for the flow of coolant. Coolant enters the tool assembly at a terminal 83 and passes through the passage 81 and out the terminal 84 into a hollow circular tube 85, formed of in sulating material. Tube 85 establishes communication be tween passage '81 in the body member 78 and passage 82 in the body member 79. Coolant flows from the tube 85 into terminal '86 and on into passage 82 and body member 79 and out terminal 87.

These body members are held in spaced relationship by means of the insulating latch 89. After opening the latch 89, it is possible to spread the body members 78 and 79 apart by turning each member in the opposite direction about an axis 90.

Inert gas may be supplied to the tool assembly 77 by a hose 91. A rubber cap 92 prevents leakage of the gas and the gas is directed to the work zone through the hollow passage 92a. Semicircular rings 93 and 94 are connected to the body members 78 and 79 by threaded fasteners 95 and 96, respectively, to form a working zone.

A transformer housing assembly 97 separates two disks 98 and 99 by a slot 100. The disks 98 and 99 are provided with aligned circular openings 101 and 102, respectively. The tool assembly 77 is positioned within the slot 100 and is held in place by a clamp screw 103, formed of insulating material and extending through the circular opening 101 and 102. Clamp screw 103 also provides the axis about which the tool assembly 77 may be rotated when the clamp screw 102 is loosened.

The transformed housing assembly 97 is formed of insulating material. Within the housing assembly 97 is the? primary coil 104 which is rectangular in cross-section and hollow to permit the flow of coolant. The primary coil 104 is continuous through the housing assembly 97 and is shaped in such a manner that there are layers of several spiral turns of the coil within each of the disks 98 and 99. Insulated washers 105 and 106 separate the tool assembly 77 and the surface of the coil 104. Fitted within the openings 107 and 108 are the insulating rings 109 and 110, respectively.

The outer end 111 of the coil 104 is slidably mounted within a square metal sleeve 112. Sleeve 112 is connected to the metallic tubes 25 and 26 by means of brazing and mounted on a metallic ring 113. A cap 114 is connected to ring 113 by threaded fasteners 115. Cap 114 has a central opening 116 which receives a tubular body 117. The body 117 is connected to the inner end 118 of the primary coil 104 by means of brazing. Aligned openings in the coil 104 and the body 117 permit the flow of coolant to the tubular body 117 and on into passage 118a in the tubular member 42. External threads 119 on the tubular body 117 are received by nut 120, which holds the body 117 in relative position with. the cap 114. A metallic receptacle 121 with a tapered opening 122 receives the body 117 which is connected to the inner end 118 of the primary coil 104. An O-ring 123 prevents leakage. The receptacle 121 is connected to the tubular member 42 which is connected to the inner conductor 59 of the coaxial cable assembly 53 by the threads 124.

The shell assembly 18 is connected coaxially within the transformer housing assembly 97 and connected to the split nut 35. As before, turning the split nut 35 will advance the transformer housing assembly 97 axially and relieve the friction at 38, permitting the shell assembly 18 and the transformer housing assembly 97 to be adjusted circumferentially in any position.

I claim:

1. In a device for connection to a coaxial cable having two electrical leads, the combination of: a cylindrical shell formed of electrically conducting material, a stationary inner conductor positioned coaxially within said shell, means insulating said inner conductor from said shell, means for connecting the electrical leads of the coaxial cable to said inner conductor and to said shell, respectively, means for mounting said shell with respect to said coaxial cable for relative axial turning movement, a pair of electrical connectors extending from said shell and said inner conductor, respectively, and means on said connectors for connection to a work coil.

2. The combination as set forth in claim 1 wherein said connecting means includes releasable lock means for securing the shell and cable in fixed angular relation.

3. The combination as set forth in claim 1 in which coolant passage means are provided in said shell and in said inner conductor for circulating a coolant therethrough.

4. The combination as set forth in claim 1 wherein said connecting means includes a split nut, a retainer ring, said ring fitting circumferentially about said split nut and holding it together, a stationary shoulder, a friction wall within the shell and connected thereto, said Wall being in frictional contact with the stationary shoulder to secure the shell and cable in fixed angular relationship.

5. In a device for connection to a coaxial cable having two electrical leads, the combination of: a cylindrical shell formed of electrically conducting material, a stationary inner conductor positioned coaxially within said shell, means insulating said inner conductor from said shell, means for connecting the electrical leads of the coaxial cable to said inner conductor and to said shell, respectively, means for mounting said shell with respect to said coaxial cable for relative axial turning movement, a transformer housing connected to said shell, a primary coil Within said housing, means for positioning one end of said coil within the inner conductor and securing the other end to the cylindrical shell, and means on said housing for connection to an induction heating tool.

6. The combination as set forth in claim 5 wherein said connecting means includes a clamp screw extending through said housing, a slot within said housing, said clamp screw adapted to mount the heating tool within said slot.

7. The combination as set forth in claim 5 wherein said connecting means includes releasable lock means for securing the shell and cable in fixed angular relation.

8. The combination as set forth in claim 5 in which 5 coolant passage means are provided in said transformer housing, said shell, and in said inner conductor for circulating a coolant therethrough.

9. The combination as set forth in claim 5 wherein said connecting means includes a split nut, a retainer ring, said ring fitting circumferentially about said split nut and holding it together, a stationary shoulder, a friction Wall Within the shell and connected thereto, said wall being in frictional contact With the stationary shoulder to secure the shell and cable in fixed angular relationship.

References Cited UNITED STATES PATENTS LARAMIE E. ASKIN, Primary Examiner US. Cl. X.R. 

